Installation for the illumination of playing fields

ABSTRACT

Illumination for a playing field is provided by a single source of artificial light supported at an elevated location at one side of the field. A portion of the light from the source is directed downwardly onto the entire surface of the field, and a portion of the light is reflected onto the field from a low-level substantially vertical reflector at the opposite side of the field.

United States Patent 1 3,619,595

[72] Inventor Richard A. Ott 755,447 3/1904 Cahill 240/3 Dotzheimer Laudstr. 130, Wiesbaden- 897,569 9/1908 Barcntzen 240/3 X Frauenstein, Germany 1,403,876 1/1922 Sperry 240/3 X [21] Appl. No. 741,100 1,494,282 5/1924 Paradis 240/3 [22] Filed June 28, 1968 595,353 l2/l897 Solomon et a1. 240/9 X [45] Patented 1971 Primary ExaminerSamuel S. Matthews Assistant Examiner-Monroe H. Hayes s4 lNSTALLATION FOR THE ILLUMINATION 0F Ar'wmeyChrisIen and Sabol PLAYING FIELDS 2 Claims, 7 Drawing Figs.

[52] US. Cl 240/3, 240/9 R, 240/4l.l [51] Int. Cl F211) 5/00 ABSTRACT; Illumination for a playing field is provided by a 0f 9, ingle source of artificial upported at an elevated location at one side of the field. A portion of the light from the source is directed downwardly onto the entire surface of the [56] References Cited field, and a portion of the light is reflected onto the field from UNITED STATES PATENTS a low-level substantially vertical reflector at the opposite side Re. 26,588 5/1969 Neely 240/3 of the field.

INSTALLATION FOR THE ILLUMINATION OF PLAYING FIELDS The invention relates to an installation for the illumination of playing fields by means of light sources which are adjustable in height and aim on poles.

In former times it was customary to illuminate playing fields with as many light sources as possible, these being arranged as uniformly as possible around the entire playing field and sometimes even above the playing field. As the games evolved into public sports competitions and usually took place before large numbers of viewers, attempts were made to develop to the optimum the illumination of the playing fields. Many different attempts were made in this direction, for example by using powerful floodlights suspended at very great heights, big banks of floodlights, or light sources carried by balloons. These attempts, however, did not lead to completely satisfactory results, so that attempts have been made recently to design illumination on a scientific basis and on a basis of precise measurements. In this manner it was found that optimum illumination can be achieved only by four light sources disposed at an appropriate height at the corners of the field. This viewpoint was put forward not only by illumination engineering institutes and scientists specializing in this field, but also by sports associations and clubs. It resulted from the fact that it was found by precise measurements that, with this illumination, the amount of light falling on each unit of area of the field is approximately equal.

Later, however, it was found that a specifically equal light distribution of this sort was not what determined the subjective reaction of the players. Instead, it was recognized as important that the four light sources always produce four shadows of the player, which are lighter or darker according to where the player is standing. Therefore, regardless of which way he was facing, the player always saw at least two shadows. The same is the case, of course, with the object used in the game-cg, a football. This, too, had four shadows of different intensity. In order to avoid this multiple formation of shadows, which gave annoyance to the players and got on their nerves, illumination equipment has recently been created in which only two diagonally arranged lights are used. In illumination of this kind, a player may indeed see only a single shadow of himself, which is lighter or darker according to where he is standing, but he still sees two shadows of all his fellow players and also of the ball, so that errors of judgment are still being caused.

The present invention is based on the observation of a sports team that had practiced on a suitable playing field by daylight and showed excellent promise, but lost, on a playing field illuminated as described above, to another team which had taken its practice on a field lighted in the same manner. As a result it was held that the reason for the loss could only have been the lighting conditions. It is from the recognition of this that the problem arises to which the invention is directed, and which consists in illuminating a playing field so as to create conditions for the players that are as close as possible to daylight conditions.

In daylight there are fundamentally two sources of light involved: on the one hand the sun (whether it be cloudy or clear), and on the other hand the entire sky as a great reflector of sunlight. Accordingly, the sun casts not black, dense shadows, but shadows that are illuminated with the intensity of the reflected light, and these shadows are also single shadows-and this is the important thing.

An illumination approximating daylight on the playing field is achieved according to the invention in that only two light sources are used for the illumination of the entire field and are arranged diagonally opposite-one another, only one of them being an electrically powered light source, and the other being a surface which reflects the light from the first, and which is best made adjustable in aim and in angle of tilt. It is also desirable to construct the electrically powered light source of a plurality of individual lights clustered into banks, thereby producing a diffuse beam of light which does not cast sharp shadows.

The reflective surfaces are, according to the invention, of such a size that they only more or less illumine the shadows produced by the electrically powered light, but themselves do not form shadows even of a player coming very close to them.

Playing field illumination systems already prepared according to the invention have proven that a team that has practiced on daylit fields can perform on the artificially lighted fields with the same assurance and calm, and without annoyance, because the illumination corresponds largely to daylight conditions.

Other objects and advantages will be apparent to those skilled in the art after reading the following specification, in connection with the drawings, in which:

FIG. 1 shows diagrammatically one form of lighting installation on a playing field in a plan view.

FIG. 2 is a cross section on line 11 of FIG. 1.

FIGS. 3 and 4 show diagrammatically in plan and in cross section the same playing field with only one light and reflective surface.

FIG. 5 shows a light source with a plurality of clustered floodlights.

FIG. 6 shows diagrammatically the shadow pattern in the prior art method of illumination using four light sources.

FIG. 7 shows the shadow pattern in the illumination system according to the invention.

The actual playing field l is surrounded by a marginal strip 2. Grandstands 3 surround the playing field. At two diagonally opposite comers, two poles are set up on the marginal strip, and the lights 4 and 5 are suspended from said pole. According to FIGS. 3 and 4, there is only one electrically powered light 12; the other light source is formed by reflective surfaces 6 and 6a, which are adjustable for aim. For this purpose, the reflectors are shown as being mounted at their respective ends on vertical standards, having trunnion connections 11 to permit tilting of the reflectors. v

In order to avoid a highly concentrated light beam, such as the kind produced by searchlights, it is desirable to construct the light source according to FIG. 5. The reflector 8 is fastened adjustably to the pole 9, and a plurality of individual lights 7 are mounted in it. FIG. 6 shows the prior art illumination of a playing field with four lights 4, 4a 5 and 5a. In this system it was possible to make the amount of light falling on each part of the playing field equal. The inventor, however, has recognized that the important thing here is not the uniform illumination of the playing field, but to prevent the player from being annoyed by shadows. In FIG. 6 it can clearly be seen that an object that is standing on the playing field throws four shadows, 4', 4a, 5 and 50'. If this object is a player, he sees, no matter which way he looks, at least two shadows of himself.

In the illumination according to the invention, as it is represented in FIG. 7, the player always sees only one of the shadows, 4' or 5', regardless of his position or the direction in which he is looking, this shadow being darker or lighter, depending on where the player is standing on the field.

Having disclosed several forms in which the invention may be practiced, it will be apparent that various modifications and improvements may be made which would come within the scope of the annexed claims:

1. Installation for the illumination of playing fields comprising an electrically powered light source mounted at one comer of a playing field at a considerable elevation above the level of the field and directed angularly downwardly to illuminate substantially all of the field directly, and a pair of substantially vertical reflective surfaces mounted for tilting about a horizontal axis to direct light reflected over the entire field at the level of the field and at the comer of the field diagonally opposite to said electrically powered light to reflect the light received therefrom upon the field.

2. The invention defined in claim 1, wherein said electrically powered light source comprises a flat reflective surface and a plurality of electric lamps arranged adjacent to each other on the forward side of the reflective surface to provide a diffused light source. 

1. Installation for the illumination of playing fields comprising an electrically powered light source mounted at one corner of a playing field at a considerable elevation above the level of the field and directed angularly downwardly to illuminate substantially all of the field directly, and a pair of substantially vertical reflective surfaces mounted for tilting about a horizontal axis to direct light reflected over the entire field at the level of the field and at the corner of the field diagonally opposite to said electrically powered light to reflect the light received therefrom upon the field.
 2. The invention defined in claim 1, wherein said electrically powered light source comprises a flat reflective surface and a plurality of electric lamps arranged adjacent to each other on the forward side of the reflective surface to provide a diffused light source. 